The present invention relates generally to an improved locking mechanism assembly that is within a cantilevered stowable seat for use in a vehicle to provide seating for passengers with the option of providing a space for a wheelchair or for storage of various articles. The invention preferably employs a cantilevered seatbase which pivots about one end from a deployed position to a stowed position, where a diagonal truss supports the rotation of the cantilevered seatbase from the deployed position to the stowed position. The seatbase is provided with a seatback having a lockable unfolded position where the seatback is raised to accommodate passengers, as well as a lockable folded intermediate position where the seatback is folded against the seatbase. The cantilevered stowable seat is stowed by folding the seatback to the folded intermediate position, actuating the single handle located on the aisle side of the seat thereby unlocking the seatbase from its folded intermediate position and raising the seatbase to its stowed position where it is locked in place. The stowable seat is deployed by actuating the single handle located on the aisle side of the seat assembly, thereby unlocking the seatbase from its stowed position and lowering the seatbase to its folded intermediate position where it is locked into place. The seatback is then unfolded to accommodate passengers in the deployed position.
The current state of the art teaches cantilevered seats employing two separate and distinct mechanical locks used to secure the seat assembly or a foot actuator and release pin combination. Both prior art methods have multiple steps and handles. Similar to U.S. Pat. No. 5,492,389 ('389), one handle and mechanical lock secures the seatbase in the deployed position, and a second handle and mechanical lock secures the seatbase in the stowed position. The '389 patent teaches two distinct and separate handles on either end of a runner track. The runner track has a sliding member that travels along the track to provide translational motion to the supporting diagonal truss, thus enabling rotation from a stowed to a deployed position. A downlock and an uplock mechanism are used to hold the sliding member in place to lock the seat in the stowed or deployed position. This invention overcomes the disadvantage of a two handle, multiple step process with one handle activation.
Another example of prior art is U.S. Pat. No. 5,489,141 ('141). The '141 device teaches a stowable seat with a seatbase and supporting member, a sliding assembly interconnecting the support member, and a pivoting assembly interconnecting the support member and permitting the base to pivot from a stowed or deployed position. The '141 device has several steps of operation and a multi-step lock and pin mechanism which holds the seat in either the stowed or deployed positions. Both of these problems are eliminated by this invention. Specifically, an operator with the '141 patent must first lower the seat back and then press a foot actuator to release the pivotable leg from the floor. The operator then lifts the pivotable leg out of two slots in the floor. When the pivotable leg reaches the retracted position, two pins are snapped into two boars. Utilizing a push bar to raise the seatbase, a system of tubes and rods are used in connection with a set of pins to lock the seatbase in the retracted position. When force is applied to the push bar, the rods slide into the tubes until the pins click into the aligned bores on the tubes and rods. Another embodiment includes a pull ring where the pins are inserted or removed manually instead of the system of tubes and rods.
This invention overcomes the '141's multiple steps and problems by having one handle that actuates both locking mechanisms within the seatbase for the stowed and deployed positions. Also, there is also only one leg in this invention instead of the complicated foot actuated system that releases the pivotable leg in the '141 patent. This invention teaches a more efficient method to lock a cantilevered stowable seat in the stowed and deployed positions with fewer parts and steps, while maintaining the structural integrity necessary for a seat component to be used in a rigorous commercial setting.